tumen often floating on the water when it meets with it.
I am of opinion that fait grows in the mine like minerals,
that coal is the produft of foffil wood, as appears
from fuch remnants as are found in the mines (#), and
that the afphaltos is produced by thewater of fome fpring.
I examined attentively thefe ftrata o f fait, comparing
them with the matter in which they are embedded. I
obferved the roof to be of gypfum with aromatic plants,
then two inches o f white fait, feparated from the gypfum
by a few threads of faline earth, then, three fingers
breadth of pure fait, with two of ftone fait, and a coat
o f earth, next another blueiih bed, followed by two
inches of fa it; and laftly, other beds alternately of earth,
and chryftaline fait to the bed of the mine, which is
gypfeous ftone undulated like the reft, defcending to
the valley, and riling on the oppoiite hills. The ftrata
o f faline earth are o f a dark blue, but thofe of fait, are
white. This mine is of a great elevation with refpeft to
the fea, for you always go up hill to it from Bayonne,
ex-cepting thofe cafual defcents which are infeparable
from mountainous countries.
[a) It has been afferted that coals being fometimes produced from clay faturated by petroleum,
may be found in any. glace or Ctuation where clay or argillaceous Hate is to be met
with, in ancient fimple or modern ilratified mountains, as well as on, and in volcanic mountains,
and that henceforth coals will not be coniidered as cpnftantly produced from trees,,
plants, and forefts, buried by inundations, though many coal mines may have had fuch an
origin. See Ferber’s mineralogical hiftory of Bohemia, page 308, note 5, prefixed, to Baron
Born's travels through Tranfilvania and Hungary, translated by R. E. Rafpe, London, 177 7*
It
It is a continual afcent from Valtierra to Agreda, the
fir ft town in Caftile, on the top of one o f the higheft
mountains in Spain called Moncayo, whofe rocks fo de-
compofe into earth, as to be covered with plants, de-
ferving the attention o f a botanift, from the great variety
thence afforded in the vegetable kingdom. From
Agreda the country is well cultivaibed to Hinojofo, without
any trees or plants, as far as Ahneriz, and: forwards
to Almaz an', on the banks of the Duero: examining this
diftricl, which produces wheat and barley, I difcoveredi
lime rock at a few feet from the furface, which for a great
extent has an outward coat of fandy foil, with quartz and
fand ftone totally different from the bottom, which gives
it the appearance of a foreign matter brought from a
diftance. The phenomenon is fingular, and thofe who
are fond of hypothefes have here an ample field to employ
their imagination.
Leaving Almazan you rife upon an eminence which
affords an extenfive profpect, the country at a diftance
having the appearance o f a plain, the eye not being able
to catch the many irregularities of ground. After fome
leagues of uncultivated land, the country improves ;
three leagues and a half further, I came to Paredes, and
crofting a barren plain arrived at Baraona, then palling
over the fteep hill of Atienza, the confines o f the two
Caftiles,